I have a 2008 Volvo S60. During the summer when I used the Air Conditioning the blower speed would kick down if I pressed the AC button. The air is definitely cold but it barely blows when in AC mode. If the heat or vent is on the blower is strong but as soon as I press the AC button it kicks down. Changing where the air blows did not improve the condition either. My mechanic didn’t have any idea what could cause this and it occurred at the end of the summer so I never got a 2nd opinion from another mechanic. Any thoughts?
There are 2 units feeding the fan and it could be either the Fan Control Module or the Climate Control Module. Since the fan works the resistor pack is good. It could be the engine coolant sensor was mentioned on a Volvo forum.